Miniature hoist



De 6, 1966 E. E. MATTHEWS ETAL 3,290,012

MINIATURE HOIST Filed Aug. 5, 1965 5 Sheets-Sheet 1 5y @is /VQZZM Afri/s.

Dec. 6, 1966 Filed Aug. 5, 1965 muni' l E. E. MATTHEWS ETAL MINIATURE HOIST "Hill 5 Sheets-Sheet 2 WW M Arrys.

Dec. 6, 1966 E. E, MATTHEWS ETAL MINIATURE HOIST Filed Aug. 5, 1965 United States Patent O 3,290,012 MINIATURE HOIST Edwin E. Matthews, St. Louis, and Arnold E. Pryhuber,

St. Charles, Mo., assignors, by mesne assignments, to

the United States of America as represented by the Secretary of the Navy Filed Aug. 5, 1965, Ser. No. 477,626 1 Claim. (Cl. 254-187) The present invention relates to a gear hoist and more particular to aminiature hoist for raising and lowering electronic equipment to be mounted in an aircraft.

In the maintenance of aircraft, and particularly in the maintenance of military aircraft, it is frequently necessary to remove electronic equipment from the aircraft for repairs. Some of the present day electronic equipment weighs several hundred pounds and the space through which the electronic equipment is raised or lowered is often very small. It is very diicult to manually handle this equipment and all heretofore known hoists are so large and heavy that they themselves become a problem to position in the aircraft.

The present invention relates to a small hoist that weighs less than one pound but yet can safely raise or lower a load weighing several hundred pounds. A cable drum is integrally attached to a rst spiroid gear and a cable has one end attached to the cable. drum and is wound and unwound therefrom. A spiroid pinion gear meshes with the first spiroid gear. The pinion gear is mounted on a splined shaft and a ratchet clutch is interposed between the splined shaft and an input shaft. A spring actuated locking device is provided to engage with the cable drum when the last turn of the cable is unwound from the cable drum.

It is therefore a general object of the present invention to provide a small lightweight gear hoist for hoisting relatively large loads.

Another object of the present invention is to provide a small lightweight gear hoist that has a safety clutch for preventing an excessive overload from damaging the hoist.

Still another object of the present invention is to provide a hoist that has locking means for preventing rotation of a cable drum when the last turn of a cable has been unwound.

Other objects and advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIGURE l is a side elevation view showing a preferred embodiment of the present invention;

FIGURE 2 is an enlarged sectional view taken on line 2-2 of FIGURE l;

FIGURE 3 is a sectional view taken on line 3-3 of FIGURE 2;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 2;

FIGURE 5 is a sectional view taken on line 5-5 of FIGURE 2, except showing a clutch in a non-drivable position; and

FIGURE 6 is a partial perspective view, of a clutch mechanism, partly broken away to show parts in section.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown a housing 11 that has a plurality of mounting holes 12 for fastening to a bulkhead, such as the frame of an aircraft. A shaft 13 is attached to housing 11 and a cable drum 14 is rotatably mounted on shaft 13. Washers and thrust bearings 16 are also provided on shaft 13 to facilitate positioning of cable drum 14 on shaft 13. Spiroid gear teeth 17 are cut 3,290,012 Patented Dec. 6, 1966 ICC on flange 18 of cable drum 14 and gear teeth 17 are in drivable mesh with teeth 19 on pinion gear 21.

As best shown in FIGURES 2, 4, 5, and 6 of the drawings, pinion gear 21 is provided with an enlarged diameter portion 22 that is provided with a large counterbore 23, and the enlarged diameter portion 22 is rotatably mounted through a wall of housing 11. One end of the enlarged diameter portion 22 is threaded and an end cap 24 is threadedly attached thereto in order to retain pinion gear 21 in position. A clutch mechanism 25 is provided within the enclosed counterbore 23 and is comprised of a clutch input shaft 26 and a clutch output shaft 27. The clutch face 28 of shaft 26 is provided with a pair of grooves 31 and 32 that are at right angles to one another and which have tapered sides with the widest portion thereof being at the surface of clutch face 28. A clutch face plate 33 is provided on one end of shaft 27 and the other end of shaft 27 is splined and engages with a splined bore 34 in pinion gear 21. Clutch face plate 33 has four slots 35 therein and four hardened steel balls 36 are provided one each in each slot 35. These balls normally rest in grooves 31 and 32. A coiled spring 37 is provided in counterbore 23 and presses against a pair of washers 38 and 39, with washer 39 being in contact with balls 36. Spring 37 retains balls 36 in grooves 31 and 32 until an overload condition exists, and torque applied to input shaft 26 is transferred through the grooves in clutch face 28 and the balls 36 to output shaft 27.

Referring now to FIGURES l, 2, and 5 of the drawings, a safety locking device is shown that automatically locks the cable drum 14 when the last turn of a cable 41 is unwound from drum 14. A latch 42 is pivotally mounted to housing 11 by shaft 43 and a spring 44 is pro.

vided to bias latch 42 against cable 41, as shown in FIGURE 5 of the drawings. When the last full turn of cable 41 is unwound from cable drum 14, the latch 42 will be biased against the outer periphery of cable drum 14, and continued rotation of cable drum 14 will cause latch 42 to drop into hole 45 in cable drum 14 and prevent further rotation of drum 14. FIGURE l of the drawings shows latch 42 engaged in hole 45. The back edge 46 of latch 42 is tapered and upon reversal of direction of input crank 40 to wind cable 41 upon cable drum 14, latchv 42 is pivoted out of hole 45 when the edge of hole 45 engages tapered edge 46.

As best shown in FIGURES 1, 2, and 3 of the drawings, cable 41, which has one end permanently attached to cable drum 14, passes around pulley 47 which is rotatably mounted by shaft 48 to boss 49 on housing 11. A shield 51 is provided on housing 11 and shield 51 has a curved portion 52 that is positioned in close proximity to pulley 47 thereby serving to keep cable 41 confined to the groove of pulley 47.

In operation, assuming a light load is being lowered, the turning of crank 40 will turn input shaft 26 which will, in turn, cause output shaft 27 to be rotated by means of clutch 25. As a splined portion of shaft 27 engages the splined bore 34 of pinion gear 21, rotation of shaft 27 causes pinion gear 21 to be rotated which, in turn, drives cable drum 14 through teeth 17 that mate with teeth 19 on pinion gear 21. When the last turn of cable 41 begins to unwind from cable drum 14, hole 45 becomes uncovered and latch 42 drops into hole 45 due to the pressure applied by spring 44. Further rotation of cable drum 14 is thereby prevented by latch 42. Any additional rotation of crank 40 causes clutch 25 to ratchet. Grooves 31 and 32 become disengaged from the balls 36 and input shaft 26 no longer drives output shaft 27.

Upon reversal of direction of crank 40, input shaft 26 is rotated until balls 36 again becomes engaged with grooves 31 and 32, whereupon additional rotation of input shaft 26 causes output shaft 27 to be rotated. ,Rotation of shaft 27 causes cable drum 14 to be rotated and latch 42 is pivoted out of hole 4S when the edge of hole 45 engages the tapered edge 46 of latch 42.

It can thus be seen that the present invention provides 5 a small hoist for lifting a relatively heavy load. Also that the hoist herein described has various safety features for protecting the hoist. Obviously many modications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

A hoist comprising:

a frame,

a cable drum rotatably mounted to said frame, said cable drum having a hole therein and having a spiroid gear on one ange thereof,

a cable having one end attached to said cable drum and being Windable thereon whereby a portion of a rst turn of said cable upon said cable drum covers said hole in said cable drum,

a spiroid pinion gear having a shaft with a splined bore therein, said pinion gear being rotatably mounted to said frame and being in mesh with said spiroid gear,

an input shaft having an enlarged diameter portion having rst and second grooves on the face thereof,

an output shaft having a splined portion on one end slidably engaging said splined bore in said pinion gear and an enlarged diameter portion having a plurality of slots therein on the other end,

a plurality of balls positioned on each in each said slot,

said balls being engageable in said grooves on said input shaft, l n

a spring surrounding said spline portion of said output shaft for biasing said balls against said face of said input shaft, l

a latch pivotally connected to said frame and engageable with said hole in said cable drum when said hole is uncovered, and

spring means for biasing said latch against said cable when said cable covers said hole, and into said hole when said hole is uncovered.

References Cited by the Examiner UNITED STATES PATENTS 1,013,106 l/1912 Balchtold 254-187 1,883,164 10/1932 Vassakos 64-29 2,053,976 9/1936 Stahl 254--173 2,587,712 3/1952 Dodge 64-29 2,769,613 1l/1956 Blosick 254-187 3,220,526 11/ 1965 Gattiker 64-29 References Cited by the Applicant UNITED STATES PATENTS 1,508,492 9/1924 Wright. 1,849,385 3/ 1932 Sekulski. 2,207,053 7/ 1940 Fivecoate et al. 2,230,947 2/ 1941 Hastings. 2,407,692 9/ 1946 Vickers. 2,450,718 10/ 1948 Darnell.

EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner. 

